Predictive CT features in ruptured abdominal aortic aneurysm.

Objective: To evaluate the CT findings including size of aneurysm, hyperattenuation crescent sign and focal discontinuity of mural calcification to predict the risk of ruptured aneurysm.

Material And Method: Records of 27 patients, who underwent Multislices Computed Tomography (MDCT) and required operative repair of abdominal aortic aneurysm from July 2000 to July 2003 were retrospectively reviewed Two radiologists evaluated the images by consensus, analyzing the aneurysm size, hyperattenuation crescent sign, and focal discontinuity of mural calcification.

Results: The authors found that the mean maximum AP diameters of the aneurysm in the ruptured and nonruptured group were 6.95 cm and 5.50 cm, respectively. All patients in the ruptured group had an aneurysm size of more than 5.0 cm. The hyperattenuation crescent sign and focal discontinuity of mural calcification had a high specificity for predicting ruptured aneurysm, 95% and 100%, respectively. There was statistical significant difference between the ruptured aneurysm and non-ruptured groups in the patients who had maximum aneurysm size more than 5 cm with positive hyperattenuation crescent sign (p < 0.041).

Conclusion: A maximum size of aneurysm greater than 5 cm with positive hyperattenuation crescent sign is a suggestive sign to predict ruptured aneurysm.